1. Technical Field
The present invention relates to a connection terminal in which a connection portion of a wire connection portion and a wire is covered with a resin covering portion and a method of manufacturing the connection terminal.
2. Related Art
Japanese Unexamined Patent Application Publication No. 2010-97704 and Japanese Unexamined Patent Application Publication No. 2010-135121 propose connection terminals in which a connection portion of a wire connection portion and a wire is covered with a resin covering portion. An example of such a connection terminal is shown in FIGS. 1 to 4B.
As shown in FIGS. 1 and 2, a connection terminal 100 includes a terminal connection portion 101 to which a partner terminal is to be connected, a wire connection portion 110 to which a wire W is connected, and a neck portion 120 connecting the terminal connection portion 101 and the wire connection portion 110. The terminal connection portion 101, the wire connection portion 110, and the neck portion 120 are formed by bending one sheet of conductive metal plate.
The terminal connection portion 101 has a rectangular cylindrical shape. A partner terminal is inserted into the cylindrical shape. The wire connection portion 110 has a U-shaped surrounding wall 111. A pair of first wire caulking portions 113 and a second wire caulking portion 114 are projected from an upper end surface of both side ends of the surrounding wall 111. A core wire 150 of the wire W is crimped by the pair of first wire caulking portions 113 through caulking and a portion of the wire W covered with a covering skin 151 is crimped by the second wire caulking portion 114 through caulking.
The neck portion 120 has a bottom wall 121 and a pair of side walls 122 installed upright from both side ends of the bottom wall 121. The bottom wall 121 and the pair of side walls 122 are formed continuously from each wall of the terminal connection portion 101 and the wire connection portion 110. The pair of side walls 122 are inclined so as to gradually make the interval therebetween narrower from the terminal connection portion 101 toward the wire connection portion 110. The width dimension of the terminal connection portion 101 is narrowed to the width dimension of the wire connection portion 110 by the neck portion 120.
The connection portion of the wire connection portion 110 and the wire W is covered with a resin covering portion 130. The resin covering portion 130 is produced by injection molding of resin.
That is, as shown in FIG. 3, the connection terminal 100 to which the wire W is connected is set to a die 140 for resin molding. The die 140 includes a lower die 141 and an upper die (not shown). FIG. 3 shows a state in which the connection terminal 100 is set to the lower die 141. Next, a resin is poured into a cavity 141a inside the lower die 141 and the upper die (not shown) and the resin covering portion 130 is produced by the poured resin being set.
A resin blocking piece 142 (shown as a virtual line in FIG. 2) of the die 140 enters the neck portion 120 during resin molding. Both side surfaces of the resin blocking piece 142 are formed as inclined planes corresponding to the pair of side walls 122. The resin blocking piece 142 blocks molten resin to prevent the molten resin from flowing from the wire connection portion 110 toward the terminal connection portion 101.
According to an above related example, when, for example, the connection terminal 100 and the core wire 150 of the wire W are made of different metallic materials (for example, the connection terminal 100 made of copper and the wire W made of aluminum), if water or the like enters the connection portion of both, a current flows due to a potential difference therebetween and corrosion is caused and so such corrosion is prevented by the resin covering portion 130.